1. Field of the Invention
The invention pertains to the field of vehicle simulators, and, more particularly, to the emulation of the look and feel of real world control devices for vehicles. In particular, the invention simulates the forces felt by the operator in manipulating the gearshift of a car with a manual transmission using a simulated car and a simulated gearshift which are computer controlled to emulate the real world forces which would be felt if an actual vehicle were manipulated in a similar fashion to the manipulation of the simulated vehicle using the simulated control device.
2. Description of the Related Art
Vehicle simulators have been known for a long time. In particular, aircraft simulators have long been known for use in training pilots. Such flight simulators are typified by U.S. Pat. No. 4,343,610 to Ghou and U.S. Pat. No. 4,345,817 to Gwynn. These two patents disclose, respectively, a motion system for providing motion of the simulator in three degrees of freedom and apparatus to widen the field of view of the pilot.
Various driving simulators are also known such as that disclosed in U.S. Pat. No. 2,806,430 to Bouju. This driving simulator employs mechanisms to vibrate the driving seat and cabin to simulate engine vibration and to provide resistance to pedal actuation and steering. This provides more realistic feedback to the driver of the simulator. A vehicle simulator which has various control devices for manipulation by the driver such as an acceleration pedal, brake pedal, clutch pedal, gear change lever and steering wheel is taught in U.S. Pat. No. 4,383,827 to Foerst. This vehicle simulator uses a digital computer to provide a road vehicle driving simulation wherein the road simulation is shown on a video display and is fully interactive with control inputs from the control devices manipulated by the driver. A driving simulator with feedback forces to a steering wheel is taught in "The Automobile Driving Simulator For Anthropogenic Research" by E. Donges, published as report No. FB-41 in Forschungsinstitut Fuer Anthropotechnik in July 1978. A vehicle simulator by McFadden Systems, Inc. of Santa Fe Springs, Calif., includes a steering control torque to be programmed into the steering wheel loader. The system consists of a DC servo unit, torque cell, servo controller, power amplifier and cables. The torque cell provides feedback for a torque servo. The servo controller/power amplifier unit contains electronic servo compensation and power amplification to drive the DC torque motor. Spring gradient variations can be made in real time via host computer commands. This steering wheel loader has been installed in the driving simulator of a major automotive manufacturer to evaluate drive/vehicle performance over a wide variety of road conditions.
A vehicle simulating arcade game produced by Atari Games, Inc. of Milpitas, Calif. and marketed under the name "Hard Drivin".TM. incorporates systems for simulating feedback forces to automobile components such as steering wheels, brakes and clutches. This device includes a gearshift device for simulating the look and feel of an actual gearshift lever with a computer driven electrically operated clutch to resist movement of the gearshift lever as appropriate to the specific situation. One embodiment of such a device for simulating the look and feel of a gearshift lever in a manual transmission is disclosed in U.S. patent application Ser. No. 296,552 to Moncrief, et al., filed Jan. 12, 1989, now U.S. Pat. No. 4,949,119 and entitled "Gearshift for a Vehicle Simulator Using Computer Controlled Realistic Real World Forces," for which the base issue fee has been paid. This reference is hereby incorporated herein by reference.
The realistic simulation of forces experienced in the gearshift system of the "Hard Drivin".TM. product, and described in the Moncrief, et al., patent application, is produced as a result of relatively involved interplay between complex hardware, firmware and software. Although the output produced is very good, the initial system cost is a concern. Thus, a need has arisen for a gearshift emulation system which can simulate under very realistic conditions those forces felt by the operator of a manual transmission shift lever in an actual vehicle, while being simple and relatively inexpensive in construction and reliable in operation over extended periods. Such a device has applications in games as well as in vehicle simulators.